]Argument not Optional error

[eeyk]

Public Sub FullPathSearch(strPath As String, _
                          ByRef Files As Collection, _
                          Optional ByVal Compare As VbCompareMethod = vbBinaryCompare, _
                          Optional ByVal strPattern As String = "*.*", _
                          Optional ByVal Attributes As VbFileAttribute = vbNormal, _
                          Optional ByVal Recursive As Boolean = False)

ziet iemand de fout in dit stukje code?